Communication cables are made with large numbers of wires in a common core and often with wires twisted together to form pairs. Depending upon the amount of twisting, the pairs have their relationship along helical paths and the distance of the successive helixes constitute the "lay" of the pair.
The invention can be used for pairing, tripling, quadding, and bunching machines used for twisting wires. It will be described on a twisting machine for making pairs; the operation being similar where more wires are used. Wires are twisted to form pairs by passing them through twisting machines where the pairs of conductors are moved through orbital movement by a flyer bow which causes the conductors entering the flyer to be twisted. The flyer can also be constructed to impart additional twist and shorter lay to the pairs as they exit from the flyer.
One of the common problems encountered with twisting machines is that the windage caused by the rapid rotation of the flyer bow through its orbital path causes the conductors to be displaced from the bow and to accumulate a loop which may catch on adjacent structure and cause the wires to break.
In order to make it impossible for such windage to overcome the centrifugal force, that holds the conductors against the flyer bow, the construction of this invention provides a groove on the inner surface of the flyer bow; and this groove is deep enough to permit the conductors to nest into the groove out of the wind that sweeps across the surface of the bow as it rotates rapidly through its orbital path.
This invention provides a flyer bow which can be used on conventional twisting machines. The groove extends for most of the length of the bow but in the preferred embodiment it terminates short of the ends of the bow so that the ends can be constructed with the usual flat surfaces for connection with the end plates of a conventional twisting machine.
Other objects, features and advantages of the invention will appear or be pointed out as the description proceeds.